Rotating electric machine system

Abstract

A rotating electric machine system is equipped with a rotating shaft, a bearing for supporting the rotating shaft in a housing, and a rotor internal flow path through which a liquid coolant flows. The rotor internal flow path is formed inside a rotor and extends along an axial direction of the rotating shaft. Groove shaped flow paths are formed in the rotating shaft. The groove shaped flow paths are recessed inwardly in a diametrical direction and extend along the axial direction of the rotating shaft. An inner circumferential surface of the bearing covers the groove shaped flow paths, and thereby constitutes one portion of the rotor internal flow path.

1 . A rotating electric machine system that is equipped with a rotating electric machine provided with a rotor including a rotating shaft and a permanent magnet, and is equipped with a housing in which the rotating shaft is rotatably supported, the rotating electric machine system comprising:
 a bearing interposed between the housing and the rotating shaft;   a liquid coolant supplying device configured to supply a liquid coolant to the rotor; and   a rotor internal flow path formed in an interior of the rotor, extending along an axial direction of the rotating shaft, and through which the liquid coolant flows,   wherein the rotating shaft includes a small diameter portion and a large diameter portion having a larger diameter than the small diameter portion, and the large diameter portion is adjacent to the small diameter portion downstream in a flow direction of the liquid coolant that flows through the rotor internal flow path,   the rotating shaft includes a groove shaped flow path that is recessed from an outer surface of the small diameter portion inwardly in a diametrical direction of the small diameter portion, and extends along the axial direction of the rotating shaft, and   the bearing is provided outward of the small diameter portion in the diametrical direction, an inner circumferential surface of the bearing covers the groove shaped flow path, and the bearing thereby constitutes one portion of the rotor internal flow path.   
     
     
         2 . The rotating electric machine system according to  claim 1 , wherein the rotor internal flow path is formed at an end part of the large diameter portion that faces toward the small diameter portion, and includes a guide flow path that is continuous with the groove shaped flow path, and
 a bottom surface of the guide flow path is an inclined surface that is inclined from an inner side in the diametrical direction of the rotating shaft toward an outer surface of the large diameter portion, as the bottom surface separates away from the small diameter portion.   
     
     
         3 . The rotating electric machine system according to  claim 1 , wherein the rotor includes a tubular member interposed between the rotating shaft and the permanent magnet in the diametrical direction of the rotating shaft, and at least one portion of the rotor internal flow path is formed between an outer surface of the rotating shaft and an inner circumferential wall of the tubular member. 
     
     
         4 . The rotating electric machine system according to  claim 1 , wherein the liquid coolant supplying device is an oil supplying device configured to supply oil as the liquid coolant, and
 the housing includes an oil supply passage in order to supply the oil as a lubricant to the bearing.   
     
     
         5 . The rotating electric machine system according to  claim 4 , further comprising a bearing holder provided in the housing and configured to retain the bearing,
 wherein the bearing holder includes a flow-through hole at a position facing toward an outer circumferential surface of the bearing, and the flow-through hole places an inner circumferential surface of the bearing holder and an outer circumferential surface of the bearing holder in communication with each other, the oil flowing through the flow-through hole.   
     
     
         6 . The rotating electric machine system according to  claim 4 , wherein the housing includes an oil discharge passage through which the oil that has passed through the rotor internal flow path and the oil supply passage is discharged to the oil supplying device. 
     
     
         7 . The rotating electric machine system according to  claim 6 , wherein the oil supplying device resupplies the oil discharged from the oil discharge passage to the rotor internal flow path and the oil supply passage. 
     
     
         8 . The rotating electric machine system according to  claim 7 , further comprising a gaseous coolant supplying device configured to supply a gaseous coolant to the bearing,
 wherein the housing includes a gaseous coolant flow path through which the gaseous coolant flows, and a gaseous coolant discharge passage through which the gaseous coolant is discharged to an exterior of the housing, and   the oil supplying device recovers the gaseous coolant that has flowed through the gaseous coolant discharge passage and the oil that has flowed through the oil discharge passage, and resupplies the oil to the oil supply passage.   
     
     
         9 . The rotating electric machine system according to  claim 8 , wherein the oil supplying device includes a gas-liquid separation device configured to separate the gaseous coolant and the oil.